There is excellent evidence that type 2 diabetes can be prevented, or at least its onset delayed, in individuals at high risk. Most of the evidence is from studies that have included people with IGT. Behavioural modification and pharmacological interventions have both been shown to be effective, and to reduce the onset of new diabetes by up to 60% or more. Overall the evidence suggests that lifestyle counselling to support behavioural change, such as losing weight (for those overweight), increasing physical activity, and eating a healthy diet is more effective than pharmacological interventions 1 . For example, for around every six people at high risk treated with lifestyle counselling one new case of diabetes will be prevented over five years, whereas to prevent one new case with an oral diabetes drug, around 11 people will need to be treated. There is evidence that the lower risk of diabetes from lifestyle counselling persists long after its discontinuation, with results from a study in China showing that the benefits were still apparent 20 years later.
Translating findings from prevention trials into the community
The challenge now is to translate the findings from the well resourced research studies into diabetes prevention initiatives that are affordable and feasible in both low- and high-income countries. The challenge includes finding the most efficient and cost-effective ways to identify people at high risk of developing diabetes, and then providing an effective intervention that is feasible and affordable within the local setting. While there are examples of such initiatives they have tended to be small and poorly evaluated. It is also clear that an initiative developed for one population or group may not be appropriate for another population or group. Thus, community initiatives aimed at the prevention of type 2 diabetes in individuals at high risk need to be developed and evaluated for the specific settings in which they will be used.
National efforts to prevent diabetes
It is acknowledged that while it is important to identify individuals at high risk of developing diabetes for preventive efforts, this will have a limited impact on the rate of diabetes at a national level. What are also needed are measures that reduce the risk across the whole population. Evidence suggests that relatively small improvements in nutrition, reductions in obesity and increases in physical activity if applied across a whole population can have a large impact on the rates of diabetes, and other chronic diseases that share the same risk factors (such as cardiovascular disease and many cancers). Much more attention needs to be given as to how to achieve such population-wide changes. The DEHKO project in Finland 2 provides an example of a comprehensive approach to diabetes prevention and management, which aims to improve nutrition and physical activity across the population, identify and provide individualized support to those at high risk of diabetes and assist with the early detection and management of those who actually have diabetes (see Box 4.2).
Cost effectiveness of prevention
Economic evaluations of approaches to identifying and providing preventive measures to people at high risk of diabetes generally suggest that these are cost effective. However, most evaluations contain many uncertainties and there is a need for further work to examine the cost effectiveness of interventions in everyday practice. There is an even greater challenge in assessing the cost effectiveness of population-wide measures.
The background paper, The Prevention of Type 2 Diabetes, on which this summary is based is available in the Downloads  section.
Box 4.1 National Diabetes Prevention Plans 3
Government initiatives should include:
—Supporting national associations and non-government organizations
—Promoting the economic case for prevention
• Community support
—Providing education in schools on nutrition and physical activity
—Promoting opportunities for physical activity through urban design (e.g. to encourage cycling and walking)
—Supporting sports facilities for the general population
• Fiscal and legislative
—Examining food pricing, labelling and advertising
—Enforcing environmental and infrastructure regulation (e.g. urban planning and transportation policy to enhance physical activity)
• Engagement of private sector
—Promoting health in the workplace
—Ensuring healthy food policies in food industry
• Media communication
—Improving level of knowledge and motivation of the population (press, TV and radio)
The Development Programme for the Prevention and Care of Diabetes in Finland (DEHKO 2000–2010) 2 was the first national diabetes programme to implement strategies for the prevention of type 2 diabetes on a population-wide scale. It is now in its final phase after nearly a decade of activity, but there are further plans for the future. DEHKO is a programme that is widely watched for the comprehensiveness in which it has worked towards reducing the incidence of type 2 diabetes in a population and, at the same time, raising the quality of diabetes care.
The FIN-D2D Project (2003–2008) within DEHKO and the follow-up project to D2D are specifically tasked with the implementation of the prevention programme for type 2 diabetes. The FIN-D2D Project has also developed new models for prevention to be disseminated to all primary healthcare centres and occupational healthcare units in Finland. The effectiveness and the cost-effectiveness of these new prevention and care practices are being evaluated. The project is now working towards making the prevention of diabetes and cardiovascular disease part of healthcare routine. More information on DEHKO, which is coordinated by the Finnish Diabetes Association, is available at www.diabetes.fi .
A project to reduce the burden of type 2 diabetes by education and lifestyle interventions in people at high risk is currently underway in Latin America. The LATIN_PLAN project will implement an intervention programme at primary healthcare level in Argentina, Brazil, Colombia, Ecuador, Peru, Uruguay and Venezuela.
The project is based on current evidence and best practice in the prevention of type 2 diabetes, especially those found in the European diabetes prevention projects (DE-PLAN and IMAGE projects). It also will develop and implement a curriculum for training diabetes prevention managers in Latin America, who will provide a basis for long-term activities at population level, and guarantee sustainability and continuity at the community level. The project is coordinated by the Research Unit of the Hospital Universitario La Paz in Madrid, Spain. More information is available from email@example.com .
1: Gillies CL, Abrams KR, Lambert PC, et al. Pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance: systematic review and meta-analysis. BMJ 2007; 334 (7588): 299.
2: Finnish Diabetes Association. Development Programme for the Prevention and Care of Diabetes in Finland DEHKO 2000-2010. 2009. http://www.diabetes.fi/sivu.php?artikkeli_id=831 
3: Alberti KG, Zimmet P, Shaw J. International Diabetes Federation: a consensus on Type 2 diabetes prevention. Diabet Med 2007; 24 (5): 451-463.